Ismail, Natheer Nori. “Experimental Study on Ion Exchange Rate of Calcium Hardness in Water Softening Process Using Strong Acid Resin DOWEX HCR S S”. Nahrain University College of Engineering Journal 19, no. 1 (January 28, 2017): 107–114. Accessed December 23, 2024. https://oldjournal.eng.nahrainuniv.edu.iq/index.php/main/article/view/50.